Means for producing and maintaining synchronous motion.



No. 704,929. Patented July l5, I902. H. A. ROWLAND, D-ecd.

H H ROWLAND Admmlstrafnx MEANS FOR PRODUCING AND MAINTAINING SYNGHRONOUSMOTION.

(Application filed Dec. 11, 1901.)

(No Model.)

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No. 704,929. Patented luly l5, I902. H. A. ROWLAND, Decd.

H. H ROWLAND. Administrairix. MEANS FOR PRODUCING AND MMNTAININGSYNGHRONOUS MOTION.

({Kpplication filegl Dec. 11, 1901.) (No Model.) 2 Sheets-Sheet 2.

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UNITED STATES PATENT OFFICE.

HENRIETTA H. ROl/VLAND, OF BALTIMORE, MARYLAND, ADMINISTRATRIX OE HENRYAUGUSTUS ROWLAND, DECEASED, ASSIGNOR TO ROWLAND TELEGRAPHIC COMPANY, OFBALTIMORE, MARYLAND, A CORPORATION OF NE\V JERSEY. I

MEANS FOR PRODUCING AND MAINTAINING SYNCHRONOUS MOTION SPECIFICATIONforming part of Letters Patent No. 704,929, dated July 15, 1902.

Original application filed July 24,1901, Serial No. 69,524. Divided andthis application filed December 11, 1901. Serial To all whom it mayconcern.-

Be it known that HENRY A. ROWLAND, deceased, late acitizen of the UnitedStates, and a resident of Baltimore city, in the State of Maryland, didinvent certain new and useful Improvements in Means for Producing andMaintaining Synchronous Motion, (Case J2) of which the following is afull, clear, and exact description, such as will enable any one I0skilled in the art to which it appertains to make and use the same.

This invention relates to improvements in means for producing andmaintaining synchronous motion between two or more rotat- .ing orvibrating bodies.

Considered more specifically, the said invention relates to improvedmeans for synchronizing dynamo-electric machines or electric motors fortelegraphic or any other purzo poses for which they may be used.

The object of the said invention is the production and maintenance ofsynchronous motion in its broadest sense, and when applied todynamo-electric machines or motors it may be for the purpose ofproducing and maintaining synchronism as between two or more machinesorit may be for the purpose of producing and maintaining synchronismbetween one machine and any other rotating or vibrating body.

The invention consists generally in providing means whereby any changeof the phase relations between the dynamo or other body to besynchronized and the dynamo or other body with which synchronism is tobe maintained results in a change in the amount of energy absorbed bythe dynamo or other body to be synchronized and a consequent maintenanceof synchronism.

More especially, the said invention consists in exerting upon the dynamoor other body to be synchronized, said dynamo or other body having aconstant tendency to accelerate its speed with relation to the body withwhich synchronism is to be maintained, a force acting to counteract thisacceleration, the said force being in the form of a load arising fromthe consumption of electrical energy or work (No model.)

done by the said body to be synchronized, this load being thrown uponthe said dynamo or other body at rapidly-recurring intervals, theduration of each interval varying as the phase between the body to besynchronized and the body with which synchronism is to be maintainedvaries. 5

The invention further consists in establishing between the bodies to besynchronized two extreme phase relations, one of which results in amaximum load on the body to be synchronized and the other in a minimumload upon said body and varying this load as the indefinite number ofphase relations between the two extremes vary, thereby imparting to thesaid body to be synchronized a different speed for each different phaserelation.

Synchronism according to this invention does not depend upon any qualityof the regulating means to tend to vibrate at a predetermined rateindependent of the driving power of either the body to be synchronizedor the body with which synchronism is to be maintained, as in the casesof the well-known tuning-fork methods; but in eontradistinction to thosemethods the said invention employs regulating devices, such ascircuit-changers, which are entirely dependent for their movement,respectively, upon the body to be synchronized and the body with whichsynchronism is to be produced or maintained. Moreover, this inventiondoes not depend for its regulation upon any reversals of the fieldmagnetism of the dynamo or motor or upon a reversal in thearmattire-current, but upon the integral eifect of rapidlyrecurringloads, which are thrown upon the dynamo or other 8 body to counteractits acceleration.

This invention furthermore relates to certain improvements originallyshown and described in the patent application of Henrietta I-I. Rowland,administratrix of the estate of Henry A. Rowland, deceased, forimprovements in telegraphicdistribution, filed July 24, 1901, andserially numbered (39,524, of which the present application is adivision.

In order to more fully describe the said in vention, reference will behad to the accompanying drawings, in which Figure 1 is a diagramillustrating the principle of the invention and showing its applicationto the synchronism of dynamos located at a distance from each other.Fig. 2 is a diagram showing the circuit-changers of Fig. 1 enlarged anddeveloped. Fig. 3 is a diagram showing the substitution of a relay forone of the rotating circuit-changers. Fig. 4is a diagram showing analternative way of connecting a synchronizer. Fig. 5 is a diagramshowing the application of the invention to the synchronizing of dynamoslocated at the ends of a duplex telegraph-line. Fig. 6 is a' sideelevation, partly in section, of a dynamo to be synchronized, showncoupled to its driving-motor; and Fig. 7 is a diagram of the armatureconnections of the said dynamo.

Similar letters and numerals refer to similar parts throughout theseveral views.

In the specific application of the invention shown in Fig. 1, Arepresents an alternatingcurrent dynamo or other rotating or vibratingbody with which synchronism is to be maintained, and A a dynamo to besynchronized. L represents a line carrying the regulating-current, whichin the case shown is delivered to said line by the dynamo A. Thisregulatirig-current, however, may be derived from any source so long asit has a periodic variation and this variation bears a fixed re lationto the body with which synchronism is to be maintained.

The dynamo A may be of any of the wellknown commercial types, but isprovided with an extra set of armature-regulating or synchronizing coilsa in addition to the regular coils a for generating'current for otherpurposes. In case the invention is applied to the synchronism ofelectric motors the coils a would simply be added to the armature of themotor. The number and proportion of these coils may of course be variedto suit special cases.

and 2 represent rotating circuit-changers, consisting each of twointerlocking crownsections and each provided with a series of brushes,the circuit changers 1 with the brushes a b c and the circuit-changer 2with the brushes cl ef. The brushes a o and df are the ring-brushes andremain constantly in contact with the same section, while theintermediate brushes Z) 6 pass first from one section to the next as thecircuit-changers rotate. The brushes afare electrically connectedthrough a resistance R and the brushes 0 and cl are connected through aresistance R. These resistances R and B. may be combined withself-induction or capacity,if desired, and by this the character of theregulation altered. The brushes 1) and e are connected, respectively, tothe terminals of the armature-regulating coils of the dynamo A.

The circuit-changer l is driven in synchronism with the dynamo A in anysuitable manner, one way being that shown in Fig. 1,

which consists in mounting the circuitchanger 1 upon the shaft'of orotherwise gearing it to a small synchronizer B-such, for example, asshown and described in Letters Patent No. (322,636, granted to Henry A.Rowland, April 4, 1899, the said synohronizerbeing governed by currentin the regulatingcircuit L.

The circuit-changer 2 is mounted on the armature-shaft of, or is drivenin any other suit able manner in synchronism with the dynamo A andpreferably at such a speed that the brush 6 passes over one segment ofthe circuit-changer for each semicycle developed by the said dynamo.

The electric motor or other device [or driving the dynamo A is set orregulated in such manner that the said dynamo will, when thesynchronizing apparatus is not in use, run faster than the dynamo A, or,more generally, the device to be synchronized normally has a tendency torun faster than the device with which synchronism is to be established,but is opposed by the action of the synchronizing apparatus.

Since the operation of the regulating apparatus above described consistsgenerally in regulating the speed of the dynamo or the other body A byvarying its load as the said dynamo A varies its speed as thevoltagesupplying power to dynamo A is varied or as the outside load ischanged, the regulat ing apparatus must be capable of throwing on thedynamo or the other body A loads of Varied degrees which shall havecertain values and which shall depend upon the speed of the dynamo A,the voltage-supplying power to dynamo A, and the load on the dynamo A,due to causes aside from the effect of the synchronizing device. Itthespeed of the dynamo A should be high, the load thrown upon the dynamo Amust be correspondingly light. If this speed is slow, the load must becorrespondingly heavy. If the voltage-supplying power to dynamo A islow, the load must be correspondingly light to compensate for lowvoltage, and if this voltage is high the load must be correspondinglyheavy. Further, if, due to any change of friction or any other cause, aheavier or lighter load is thrown 011 the driving power of dynamo A thismust be compensated for by a corresponding change in the load producedby the synchronizing device. There are therefore two extremeconditionsone of maximum speed and minimum load and the other of minimumspeed and maximum loadand between the two an infinite number ofconditions of speed and load. Foreach of these extreme conditions thereis a definite phase relation between the bodies between whichsynchronism is to be maintained, and therefore between the brushes ofthe respective circuit-changers, and as many different phase relationsbetween the two extremes as there are different speeds between the twobodies. Thus let it be assumed that at a given instant the brushes of:the circuit changers lie upon the line 00 a Fig. 2. If then we attemptto trace the circuit from one of the dynamo-brushes a to the other, itwill be seen that thecircuit is not complete, as the brushes e and f lieat that instant upon separate sections of the circuit-changer 2.Likewise when the circuit-changers advance in the direction of thearrows, Fig. 2, until the brushes 1) and 6 come in contact with the nextsegments the circuit from the dynamo-brushes 0L3 will be broken acrossthe brushes a and Z). Therefore as long as the circuit-changer brushesmaintain this phase relation no extra retarding effect will be exertedupon the dynamo A, as by connecting into its armature-circuit theresistances (or other electrical constants) R and R, or it may be statedgenerally that so long as the brush b arrives upon any given point ofone of the segments of the left-hand section of its circuit-changer atthe same time that the brush 6 arrives upon a corresponding point of oneof the segments of the left-hand section of its circuit-changers and solong as the phase relation above set forth between the brushes 1) and 6exists while they are also passing over the right-hand sections of therespective circuit-changers, no retarding effect or extra load will beplaced upon the dynamo A or other body to be synchronized. This is thephase relation of minimum load. In other words, this is one of theextreme conditions under which the dynamo A may run in synchronism. Theother extreme condition or phase relation of maximum load exists whenthe relations between the brushes of the respective circuitchangers issuch that as the brush Z) arrives upon a given point of a segment of theleft-hand section of its circuit-changer the brush 6 arrives upon acorresponding point of a segment of the right-hand section of itscircuit-changer and when they also arrive upon corresponding points oftheir respective right and left hand sections-as, for example, when thebrushes 0L b c are upon the line so as and the brushes (1 c f are uponthe line to to. It will be observed that as long as this phase relationis maintained the resistances (or other electrical constants) R and Rwill be connected in the armature-circuit. Let it next be assumed thatthe phase relation that the brushes of the circuit-changer 1 bear tothose of the circuit changer 2 is the intermediate relation between thetwo extremes above considered, or, in other words, let us assume thatthe circuitchanger 2 has advanced with respect to the circuit-changer 1until the brushes occupy the positions in which they are indicated bydotted lines, Fig. 2. In this intermediate p0 sition of the brushes theload is thrown on the dynamo periodically, the duration of such periodbeing half that of either of the extreme cases above set forth, or, inother words, for half the time the brushes are passing over thesuccessive segments instead of all the time.

If the displacement of the brushes is equal to one twentyfourth of arevolution, or, more generally, to one-quarter of a segment, then theduration of the rapidly-recurring intervals for which the load is thrownupon the dynamo is correspondingly diminished. Therefore between the twoextreme relations of the brushes set forth there are an infinite numberof phase relations, for each of which the integral effect of the loadperiodically thrown on and off, as before mentioned, is to reduce thespeed of the dynamo by an amount depending upon the integral value ofthis load, so that the circuit-changer 2 may have a different speed foreach of the phase relations of the circuit-changer brushes and a stateof synchronism. The retarding effect is therefore a function of thedifference in phase between the circuit-changers, and hence between thedynamos or other devices to be synchronized, this function beingdependent upon the electrical constants of the local regulating-circuitor in the case shown the circuit of the dynamo regulating-coils. If thiscircuit consists only of resistance and has no self-induction orcapacity immediately upon its being closed, the current therein attainsits full value and so remains while the circuit remains completed, andin this case load thrown upon the dynamo will be directly proportionalto the phase difierence between the circuit-changer brushes; but if thiscircuit contains self-induction or capacity the form of this relationwill be somewhat altered.

For the purpose of illustration let it be assumed that in the case ofthe first extreme condition-viz., that of no load upon the dynamoitsspeed is fifteen hundred revolutions per minute, that for the conditionof constant load or the other extreme condition assumed in .theforegoing description the speed of the dynamo is one thousandrevolutions per minute, and that a state of synchronism exists when theload is on the dynamo half the time and off half the time or theintermediate condition above assumed, and that the speed of the dynamofor this con dition is twelve hundred and fifty revolutions per minute.Then if circuit-changer 2 accelerates its speed relation tocircuit-changer 1 the relative phase of the brushes Z) and ewill bemomentarily changed in such a manner, as will be readily seen from theforegoing description and Fig. 2, that the duration of the intervals forwhich a load is on the dynamo will be increased, and as a consequencethe circuit changer 2 will lessen its speed and in its turn willdiminish the duration of the above mentioned interval, and a state ofequilibrium is attained when the phase relation between the brushes Z)and e is that which corresponds to a speed equal to the speed ofcircuit-changer 1 at that time.

For illustrating the principle of the invention it has been assumed thatthe circuitchangers were both of the form shown in Figs. 1 and 2; butthe invention is by no means confined to this specific arrangement. InFig. 3 is shown a case in which the circuitchanger l is replaced by arelay 3, which is operated by current from the dynamo A or other source.This relay is represented as being a polar relay; but in some cases itmay be replaced by a neutral relay, if desired. The relay 3 is theelectrical equivalent of the circuit-changer 1 and its three brushes,the tongue of the relay being equivalent to the brush 1) and thecontacts g and h the equivalents of the brushes a cl. As the relay 3 isoperated by the current from the dynamo A, the vibration of its tonguebetween its cont acts will have the same periodicity as the current fromthe said dynamo, and hence the relay-tongue will pass from one contactto the other as the brush e passes over the insulation between twoconsecutive segments and remains against its respective contacts as thesaid brush passes over first one segment of the right-hand section andthen a segment of the left-hand section of its circuit-changer. Theregulating effect of this arrangement is just the same as in the case ofthe arrangement shown in Figs. 1 and 2; in this latter case theregulation depending upon the difference in the phase of vibration ofthe relay 3 and the angular phase of the circuitchanger 2.

It will be seen that in the event that relay 3 is employed in the placeof the circuitchanger 1 there is no necessity for employing a rotatingdevice such as the synchronizer B to maintain the circuit-changer insynchronism with the dynamo A. There are, however, several advantages inusing the synchronizer and circuit-changer 1 instead of the relay,especially if the dynamo A is large. The relay-tongue is more sensitiveto the variations in the current than the-synchronizer and has lessinertia than has the synchronizer to keep it going, notwithstandingmomentary interruptions in the current. Moreover, the action of therotating circuit-changer is more positive and easy of adjustment thanthat of the relay.

If desired, the rotating circuit-changer 2 may also be replaced by arelay. Moreover, these circuit-changers may be replaced by any suitabledevices which will accomplish the same end.

Instead of operating the synchronizer upon the main line direct, asshown in Fig. 1, it may be operated upon a relayed circuit, as shown inFig. 4, the periodicallyvarying current in the circuit at forsynchronism being produced by the alternate charging and discharging ofthe condensers 6, connected across the terminals of a source ofconstantpotential current acting through the vibrating tongue of therelay S. This is simply an alternative arrangement for connecting asynchronizer and forms no immediate part of the present invention.

A. special application of the present invention arises in a case whereit is necessary to operate two alternating-current dynamos insynchronism at widelyseparated points. Such a case arises in themultiplex transmission of telegraphic messages through central stationslocated at the ends of duplex lines employing alternatingcurrents. Suchan application of the invention is shown in Fig. 5. The connections forsynchronizing the dynamo A are exactly the same as shown in Fig. 3, theline L being simply a duplex line and the relays 3 3' therefore neutralto the effects of the dynamo at their respective ends of the line.

Any suitable means may be employed for driving the dynamo A atapproximately constant speed. For example, a direct-current motor F maybe coupled directly to the shaft of the dynamo, as shown in Fig. 6.

In addition to the arrangement shown for synchronizing the dynamo itsmotion may be further steadied by the employment of a mercury-damper,such as indicated by G in Fig. 7. This damper simply consists of aflywheel with a hollow rim, in which is carried mercury or othersuitable liquid, which by its viscosity tends to deaden or damp anyoscillatory vibrations from a uniform motion. This damper, however,forms no essential part of the present invention and may or may not beused as occasion may demand.

From the foregoing description it will be readily seen that thisinvention is not 0011- fined to the synchronism of dynamo-electricmachines alone, but to any moving bodies which may be synchronized afterthe manner herein shown and for any purposes for which this synchronousmotion may be useful or available. Inasmuch as the synchronism dependsupon a retarding effect produced in one case by the absorption ofelectrical energy it is quite immaterial, so far as the principle ofthis invention is concerned, whether the coils that absorb this energyare mounted on a dynamo-armature, motor-armature,or any other device bywhich the coils may be made to absorb energy, and thereby do work andexert the requisite retarding effect. Moreover, in the case of a dynamodriven by an electric motor, as herein shown, we have an example of theapplication of the invention to synchronizing both dynamo and motorsimultaneously, since, as they are direct-coupled, the synchronism ofone is necessarily imparted to the other.

Having thus described this invention, what is claimed, and desired to besecured by Letters Patent of the United States, is-

1. In a synchronous system, the combination with a dynamo-electricmachine,of a body with which said dynamo is to be synchronized,acircuit-changer controlled by the said dynamo, and a circuit-changercontrolled by said body, an electric circuit completed from thearmature-coils of said dynamo through both of said circuit-changers atrapidly-recurring intervals, electric energy absorbing means included insaid circuit and exerting a continuous synchronizing effect upon saiddynamo, by varying the energy absorbed by said dynamo with everyvariation in the speed of the body with which synchronism is to bemaintained.

2. In a synchronous system, the combination with a dynamo-electricmachine, of a body with which said dynamo is to be synchronized, acircuit changer controlled by the said dynamo, and a circuit-changercontrolled bythe said body,an electriccircuitcompleted from thearmature-coils of said dynamo through both of said circuit-changers atrapidly-recurring intervals, electric-energy-absorbing means included insaid circuit and exerting a continuous synchronizing effect upon saiddynamo, by varying the energy absorbed by said dynamo with everyvariation in the speed of the body with which synchronism is to bemaintained, said synchronizing effect being independent of the polarityof the current in the energy-absorbing circuit.

3. In a synchronous system, the combination With the dynamo-electricmachine, of a body with which said dynamo is to be synchronized, saiddynamo havinga normal tendency to accelerate its speed relative to thatof said body, a circuit-changer controlled by the said dynamo, and acircuit-changer controlled by the said body, an electric circuitcompleted from the armature-coils by and through both of saidcircuit-changers at rapidly-recurring intervals,electric-energy-absorbing means included in said circuit, and exerting acontinuous synchronizing effect by varying the energy absorbed by saiddynamo with every variation in the speed of the body with whichsynchronism is to be maintained.

at. In a synchronous system, the combination with an electric dynamo ormotor and a body with which said dynamo is to be synchronized, of meansfor exerting a continuous regulating effect upon said dynamo or motor,said effect being the integral effect of a series of rapidly-recurringloads thrown upon said dynamo or motor, the duration of each of saidloads varying with every change of speed of the said body with which thedynamo or motor is being synchronized.

5. In a synchronizing system, the combination with an electric dynamo ormotor and a body with which said dynamo or motor is to be synchronized,of means for exerting a continuous regulating eifect upon said dynamo ormotor, said effect being the integral effect of a series ofrapidly-recurring loads thrown upon said dynamo or motor, the durationof each of said loads varying with every change of speed of the saidbody with which the dynamo or motor is being synchronized, saidregulating effect being independent of the polarity of the current ineither of the ele ments of the said dynamo or motor.

6. In a synchronous system, the combination with a body with whichsynchronism is to be maintained and an electricdynamo or motor to besynchronized, of a set of regulating-coils carried by said dynamo ormotor, electrical-energy-absorbing means, an electric circuit includingsaid energy-absorbing means, and the regulating-coils of said dynamo ormotor, circuit-changing devices for continuously connecting saidenergy-absorbing means in circuit with said regulatingcoils anddisconnecting the same therefrom at rapidly-recurring intervals, theduration of said intervals changing as the said dynamo or motor variesits phase with respect to the body with which synchronism is to be maintained.

7. In a synchronous system, the combination with a body with whichsynchronism is to be maintained and an electric dynamo or motor to besynchronized, regulating-coils carried by said dynamo or motor, andcontinuously-acting automatic means for throwingan intermittent loadupon the coils ofsaid dynamo or motor, said load varying with everychange in speed of the said body with which synchronism is to bemaintained.

8. In a synchronous system, the combination with a body with whichsynchronism is to be maintained and an electric dynamo or motor to besynchronized, said dynamo or motor having a normal tendency toaccelerate its speed relative to said body, electricalenergy-absorbingmeans adapted to exert a retarding effect on the speed of said dynamo ormotor independent of the polarity of the current therethrough, and meansfor connecting said energy-absorbing means into the circuit of saiddynamo or motor, and disconnecting the same therefrom at intervalsvarying in duration with the change of phase between the dynamo or motorand said body.

9. In a synchronous system, the following instrumentalities, viz., abody with which synchronism is to be maintained and a body to besynchronized, a moving contact-maker governed by the first-named body,and a moving contact-maker governed by the body to be synchronized, anelectric circuit including both of said contact-makers, electricalenergy-absorbing means adapted to be connected in circuit with both ofsaid contactmakers, and disconnected therefrom intermittently, and toaccelerate a retarding effect upon the body to be synchronizedindependent of the polarity of the current in said circuit, saidretarding effect being the continuous integral result of a series ofrapidly-recurring loads thrown upon said body to be synchronized by saidenergy absorbing means, the time for which said loads are on said bodyvarying as the difference in phase between the two bodies varies.

10. In a synchronous system, the combina tion with a controllingline-circuit carrying a periodically-varying electric current, a movingcontact-maker controlled by the current in said circuit, an electricdynamo or motor to be synchronized, a moving contact-maker controlled bysaid dynamo or motor, and an electric circuit including both of saidcontactmakers and the armature of said dynamo or motor, anelectric-energy-absorbing means adapted to be connected in said circuitthrough the instrumentality of said contactmakers at regular andrapidly-recurring intervals, the duration of said intervals varying asthe said dynamo or motor varies its phase with respect to the body Withwhich synchronism is to be maintained.

11. In a synchronous system, the combination with a controllingline-circuit, of a dynamo-electric machine delivering aperiodically-varying current thereto, a moving contact-maker controlledby the current in said circuit, a dynamo-electric machine to besynchronized, a moving contact-maker controlled thereby, electricalresistance connected to the armature of said last-named dynamo, andconnected in circuit therewith and with both of said contact makers anddisconnected therefrom at regular intervals, the said intervals varyingin duration with the change of phase between said dynamos, and exertinga continuous synchronizing effect upon the dynamo to be synchronized,independent of roe-s29 the polarity of the current in either of theelements of said dynamo.

12. In a synchronous system, the following instrumentalities, viz., aline carryinga controlling electric current, a synchronous 1notorgoverned by the said controlling-current, a moving contact-makercontrolled by the said synchronous motor, a dynamoelectric machine ormotor to be synchronized, a moving contact-maker controlled by saiddynamo or motor, said dynamo or motor having atendency to accelerate itsspeed with relation to the said synchronous motor, and means forretarding said acceleration, said means being electrical resistanceconnected in the circuit of said dynamo or motor at intervals varying induration as the phase between the said motor or dynamo and saidsynchronous m0- t-or varies.

In testimony whereof I affix my signature in the presence of tWoWitnesses.

I-IENRIETA H. ROWLAND, Admin isMatrix of the estate of Zi enrg AugustusRowland, deceased.

lVitnesses:

COLUMBUS OD. LEE, 1). N. SILLs.

